Acne Scarring: The Latest Information 2019
Scarring is the result of an abnormal wound healing response following cutaneous inflammation with excessive matrix degradation and atypical collagen biosynthesis. Early and definitive treatment of acne is invaluable for the prevention of associated scarring.
(?Acne) scars can cause significant disfigurement, which in turn can have devastating psychosocial implications. Acne scars are infamously renowned for being recalcitrant to treatment and often a multimodal approach is required to achieve the desired cosmetic result.
Scar classification and subtyping can guide treatment options. Mild scarring is not obvious to the observer at 50 cm, moderate scarring is obvious at 50 cm and severe scarring is obvious at distances greater than 50 cm.
Classification: 2 categories Atrophic and Hypertrophic scarring
Most common type of acne scarring. Destruction and loss of collagen and elastin in the dermis, as well as atrophy in the superficial subcutaneous fat result in contraction and subsequent tethering down of the epidermis.
Atrophic scarring can be categorised into the following groups:
- Ice pick scars:
- Less than 2mm wide, narrow, deep, sharply demarcated
- Can extend into deep dermis/sub-cutaneous tissue
- Wider at epithelial surface and taper downwards
- Resistant to most skin resurfacing options (due to their depth)
- Rolling scars:
- 4 – 5 mm wide, more shallow, undulating appearance
- Rise and fall of skin surface due to fibrous anchoring of dermis to subcutis
- Requires treatment at subdermal level
- Boxcar scars:
- Wider at the base, does not taper
- Round to oval depressions in the skin with crisp margins
- Can be shallow [less than 0.5mm deep] or deep [more than 0.5mm deep]
Represents collagen gain subsequent to lesion resolution. The result is a firm, raised papule or plaque.
Hypertrophic scars develop within 4-8 weeks of injury with rapid growth for 6 months. They do not extend beyond the margins of the injury and are not progressive; in fact regression is a possibility after 12-18 months. Recurrence rates after revision are low.
Keloids on the other hand are progressive and extend beyond the margins of the injury/ lesion. Regression is unheard of.
Keloids can develop up to several years after even minor injury. They have a high recurrence rate after revision.
The appearance of both atrophic and hypertrophic scars, are often highlighted by either erythema and/ or hyperpigmentation. This aspect of acne scarring should be addressed early as it can make a drastic difference to the overall appearance of the scarring.
Other important considerations in the management plan include:
- Acne status –active or resolved?
- Wound healing – recent Isotretinoin use?
- Other skin conditions/ risk of Koebnerization?
- Skin type and risk of pigmentary changes?
- Imperative to have direct lighting overhead, this accentuates the scars.
- Assess type/colour /depth/location- scars on the body are less responsive than facial scars and take longer to heal as there are less pilosebaceous units from which regeneration occur.
Factors that can influence treatment outcomes should be assessed.
- Scar distensibility – ice pick and tethered scars do not respond well to dermal fillers.
- Palpable fibrosis beneath scars – necessitates excision or subcision prior to other treatments.
- Keloidal or hypertrophic scars in other body areas?
- Skin colour (Fitzpatrick Skin Typing)
Example: 3 Step Treatment Plan
- Initial treatment phase:
- Treatment of erythema with PDL (Pulsed dye lasers 585 or 595 nm) or BBL (Broadband light) or vascular lasers, 532 /577.
- Treatment of post-inflammatory hyperpigmentation ( HQ/tretinoin/pigment lasers)
- Focal treatment to target resistant scars (these scars often require subsequent treatments so it’s beneficial to start with them)
- Subcision: the idea is to cut the underlying tether. Bevelled 25/27/18 and or 20 gauge needles can be used depending on the scars to be treated.
Needle is placed in dermis with the bevel flat and then moved (ante-and retrograde) through the scar in a fanning pattern. The needle is then rotated 90 degrees and the fan repeated. Follow with pressure.
- TCA Cross: Chemical Reconstruction Of Skin Scars using high concentrations (70-100%) Trichloracetic acid. A very small amount of TCA is placed in the base of the scar, a toothpick is most commonly used but other methods can also be used. The interior lining of the scar undergoes a chemical peeling process, new collagen is then formed in the scar with resultant decrease in the depth and severity of the scar. The desired end-point on the day of treatment is a small area of “frosting” or whitening. This can be visible or up to 12 hours, after which only a bit of redness can be seen. A small scab falls off after 3-7 days. Treatment can be repeated at 4-8 week intervals. TCA Cross is the most efficacious treatment to treat deep scars safely. The procedure is very well tolerated and rarely requires any form of anaesthesia. Sun protection is essential for the first week after treatment.
- Collagen remodelling procedures:
Non -fractionated ablative (Full field ablation): 2940 nm Er:Yag or 10600nm Co2 lasers can be used- this is a very aggressive but also very effective treatment option. Typically one treatment would suffice but down time in the order of 1-2 weeks is standard. Potential adverse effects including: persistent erythema, infection, post-inflammatory hyperpigmentation, scarring and rarely hypopigmentation should be considered.
Fractionated ablative: Er:YAG/ YSSG and CO2 when used in fractionated mode is less aggressive with faster recovery periods. Optimum results might require repeat procedures.
Fractionated non-ablative: 1540 or 1550 nm non-ablative lasers have recovery times of only 1-3 days, however multiple treatments are required to achieve satisfactory results.
2. Chemical peels:
Superficial – SCA / glycolic / lactic / Jessner (epidermal peel)
Medium depth – Jessner plus 10 – 25%? TCA (to level of papillary dermis)
Deep – phenol containing (to level of reticular dermis) [risk of cardiac toxicity/nerve damage]
- Dermabrasion -deeper than microdermabrasion with a high risk for postoperative scarring/ pigmentary changes and milia formation
- Radio-frequency- microneedle bipolar RF and fractional bipolar RF has been proven beneficial with an improvement of 25-75% after 3-4 treatments. It works by passing a current through the dermis which produces small thermal wounds, these in turn, stimulate collagen production.
- Skin needling
- Adjunctive therapies:
- Dermal fillers- this is our preferred method for rolling scars. Results are virtually immediate which brings hope to patients. It’s important to use a filler with low hygroscopy and mild to moderate crosslinking. During placement, modified subcision is performed to release underlying tethers. Minimal bruising and swelling settles promptly. Results have great longevity due to local increase in collagen production, secondary to both trauma and dermal filler.
- Biostimulators- certain fillers have biostimulatory effects, meaning that they stimulate the skin’s fibroblasts to produce more collagen.
- PRP- platelet rich plasma is rich with cytokines and growth factors, which work together to regenerate and stimulate the production of new collagen. The benefit with PRP is that it is autologous with minimal risk of allergy/ adverse outcomes.
Summary of treatment options:
Ice pick and box car scars:
- Punch grafting
- TCA cross
Atrophic and Rolling scars:
- Fillers/fat transfer
- Skin needling
- Laser resurfacing
- Intralesional steroid injections – 0.1 – 0.2 ml/cm maximum 1 – 2ml every 4-8 weeks
- Kenacort A10 (Triamcinolone acetonide) 10mg/ml for hypertrophic scars
- Kenacort A40 (Triamcinolone acetonide) 40mg/ml for keloidal scars
- Cryotherapy – 10-20 freeze/thaw cycles
- Fractionated non-ablative laser
- 5FU 50 mg/ml
- Interferon alpha2b
- Silicone gel sheeting (24hrs for 1 – 12 months)
Adverse effects of intra-lesional steroids include: skin atrophy and telangiectasia.